(void) cast strlcpy() / strlcat() / snprintf() that cannot truncate

(void) cast a few calls that are ok to truncate because they are not used
in anything critical / unsafe, but just to make some debug/info logs a bit
more informative

diff --git a/usr.sbin/smtpd/mta.c b/usr.sbin/smtpd/mta.c
index f3ad4f1..5744a17 100644 (file)
--- a/usr.sbin/smtpd/mta.c
+++ b/usr.sbin/smtpd/mta.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mta.c,v 1.185 2014/04/04 16:10:42 eric Exp $  */
+/*     $OpenBSD: mta.c,v 1.186 2014/04/19 13:32:07 gilles Exp $        */
 
 /*
  * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -243,7 +243,7 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                                TAILQ_INSERT_TAIL(&relay->tasks, task, entry);
                                task->msgid = evpid_to_msgid(evp.id);
                                if (evp.sender.user[0] || evp.sender.domain[0])
-                                       snprintf(buf, sizeof buf, "%s@%s",
+                                       (void)snprintf(buf, sizeof buf, "%s@%s",
                                            evp.sender.user, evp.sender.domain);
                                else
                                        buf[0] = '\0';
@@ -254,21 +254,21 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                        e = xcalloc(1, sizeof *e, "mta_envelope");
                        e->id = evp.id;
                        e->creation = evp.creation;
-                       snprintf(buf, sizeof buf, "%s@%s",
+                       (void)snprintf(buf, sizeof buf, "%s@%s",
                            evp.dest.user, evp.dest.domain);
                        e->dest = xstrdup(buf, "mta_envelope:dest");
-                       snprintf(buf, sizeof buf, "%s@%s",
+                       (void)snprintf(buf, sizeof buf, "%s@%s",
                            evp.rcpt.user, evp.rcpt.domain);
                        if (strcmp(buf, e->dest))
                                e->rcpt = xstrdup(buf, "mta_envelope:rcpt");
                        e->task = task;
                        if (evp.dsn_orcpt.user[0] && evp.dsn_orcpt.domain[0]) {
-                               snprintf(buf, sizeof buf, "%s@%s",
+                               (void)snprintf(buf, sizeof buf, "%s@%s",
                                    evp.dsn_orcpt.user, evp.dsn_orcpt.domain);
                                e->dsn_orcpt = xstrdup(buf,
                                    "mta_envelope:dsn_orcpt");
                        }
-                       strlcpy(e->dsn_envid, evp.dsn_envid,
+                       (void)strlcpy(e->dsn_envid, evp.dsn_envid,
                            sizeof e->dsn_envid);
                        e->dsn_notify = evp.dsn_notify;
                        e->dsn_ret = evp.dsn_ret;
@@ -446,7 +446,7 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                case IMSG_CTL_MTA_SHOW_HOSTS:
                        t = time(NULL);
                        SPLAY_FOREACH(host, mta_host_tree, &hosts) {
-                               snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                    "%s %s refcount=%d nconn=%zu lastconn=%s",
                                    sockaddr_to_text(host->sa),
                                    host->ptrname,
@@ -472,7 +472,7 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                case IMSG_CTL_MTA_SHOW_ROUTES:
                        SPLAY_FOREACH(route, mta_route_tree, &routes) {
                                v = runq_pending(runq_route, NULL, route, &t);
-                               snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                    "%llu. %s %c%c%c%c nconn=%zu nerror=%d penalty=%d timeout=%s",
                                    (unsigned long long)route->id,
                                    mta_route_to_text(route),
@@ -496,7 +496,7 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                        iter = NULL;
                        while (dict_iter(&hoststat, &iter, &hostname,
                                (void **)&hs)) {
-                               snprintf(buf, sizeof(buf),
+                               (void)snprintf(buf, sizeof(buf),
                                    "%s|%llu|%s",
                                    hostname, (unsigned long long) hs->tm,
                                    hs->error);
@@ -516,8 +516,9 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                        m_end(&m);
                        source = mta_source((struct sockaddr*)&ss);
                        if (strlen(dom)) {
-                               strlcpy(buf, dom, sizeof(buf));
-                               mta_block(source, buf);
+                               if (!(strlcpy(buf, dom, sizeof(buf))
+                                       >= sizeof(buf)))
+                                       mta_block(source, buf);
                        }
                        else
                                mta_block(source, NULL);
@@ -532,8 +533,9 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
                        m_end(&m);
                        source = mta_source((struct sockaddr*)&ss);
                        if (strlen(dom)) {
-                               strlcpy(buf, dom, sizeof(buf));
-                               mta_unblock(source, buf);
+                               if (!(strlcpy(buf, dom, sizeof(buf))
+                                       >= sizeof(buf)))
+                                       mta_unblock(source, buf);
                        }
                        else
                                mta_unblock(source, NULL);
@@ -543,7 +545,7 @@ mta_imsg(struct mproc *p, struct imsg *imsg)
 
                case IMSG_CTL_MTA_SHOW_BLOCK:
                        SPLAY_FOREACH(block, mta_block_tree, &blocks) {
-                               snprintf(buf, sizeof(buf), "%s -> %s",
+                               (void)snprintf(buf, sizeof(buf), "%s -> %s",
                                    mta_source_to_text(block->source),
                                    block->domain ? block->domain : "*");
                                m_compose(p, IMSG_CTL_MTA_SHOW_BLOCK,
@@ -779,7 +781,7 @@ mta_delivery_log(struct mta_envelope *e, const char *source, const char *relay,
 
        e->delivery = delivery;
        if (status)
-               strlcpy(e->status, status, sizeof(e->status));
+               (void)strlcpy(e->status, status, sizeof(e->status));
 }
 
 void
@@ -1318,15 +1320,15 @@ mta_drain(struct mta_relay *r)
        if (r->status & RELAY_WAITMASK) {
                buf[0] = '\0';
                if (r->status & RELAY_WAIT_MX)
-                       strlcat(buf, " MX", sizeof buf);
+                       (void)strlcat(buf, " MX", sizeof buf);
                if (r->status & RELAY_WAIT_PREFERENCE)
-                       strlcat(buf, " preference", sizeof buf);
+                       (void)strlcat(buf, " preference", sizeof buf);
                if (r->status & RELAY_WAIT_SECRET)
-                       strlcat(buf, " secret", sizeof buf);
+                       (void)strlcat(buf, " secret", sizeof buf);
                if (r->status & RELAY_WAIT_SOURCE)
-                       strlcat(buf, " source", sizeof buf);
+                       (void)strlcat(buf, " source", sizeof buf);
                if (r->status & RELAY_WAIT_CONNECTOR)
-                       strlcat(buf, " connector", sizeof buf);
+                       (void)strlcat(buf, " connector", sizeof buf);
                log_debug("debug: mta: %s waiting for%s",
                    mta_relay_to_text(r), buf);
                return;
@@ -1742,68 +1744,68 @@ mta_relay_to_text(struct mta_relay *relay)
        char             tmp[32];
        const char      *sep = ",";
 
-       snprintf(buf, sizeof buf, "[relay:%s", relay->domain->name);
+       (void)snprintf(buf, sizeof buf, "[relay:%s", relay->domain->name);
 
        if (relay->port) {
-               strlcat(buf, sep, sizeof buf);
-               snprintf(tmp, sizeof tmp, "port=%d", (int)relay->port);
-               strlcat(buf, tmp, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)snprintf(tmp, sizeof tmp, "port=%d", (int)relay->port);
+               (void)strlcat(buf, tmp, sizeof buf);
        }
 
        if (relay->flags & RELAY_STARTTLS) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "starttls", sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "starttls", sizeof buf);
        }
 
        if (relay->flags & RELAY_SMTPS) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "smtps", sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "smtps", sizeof buf);
        }
 
        if (relay->flags & RELAY_AUTH) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "auth=", sizeof buf);
-               strlcat(buf, relay->authtable, sizeof buf);
-               strlcat(buf, ":", sizeof buf);
-               strlcat(buf, relay->authlabel, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "auth=", sizeof buf);
+               (void)strlcat(buf, relay->authtable, sizeof buf);
+               (void)strlcat(buf, ":", sizeof buf);
+               (void)strlcat(buf, relay->authlabel, sizeof buf);
        }
 
        if (relay->pki_name) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "pki_name=", sizeof buf);
-               strlcat(buf, relay->pki_name, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "pki_name=", sizeof buf);
+               (void)strlcat(buf, relay->pki_name, sizeof buf);
        }
 
        if (relay->flags & RELAY_MX) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "mx", sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "mx", sizeof buf);
        }
 
        if (relay->backupname) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "backup=", sizeof buf);
-               strlcat(buf, relay->backupname, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "backup=", sizeof buf);
+               (void)strlcat(buf, relay->backupname, sizeof buf);
        }
 
        if (relay->sourcetable) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "sourcetable=", sizeof buf);
-               strlcat(buf, relay->sourcetable, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "sourcetable=", sizeof buf);
+               (void)strlcat(buf, relay->sourcetable, sizeof buf);
        }
 
        if (relay->helotable) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "helotable=", sizeof buf);
-               strlcat(buf, relay->helotable, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "helotable=", sizeof buf);
+               (void)strlcat(buf, relay->helotable, sizeof buf);
        }
 
        if (relay->heloname) {
-               strlcat(buf, sep, sizeof buf);
-               strlcat(buf, "heloname=", sizeof buf);
-               strlcat(buf, relay->heloname, sizeof buf);
+               (void)strlcat(buf, sep, sizeof buf);
+               (void)strlcat(buf, "heloname=", sizeof buf);
+               (void)strlcat(buf, relay->heloname, sizeof buf);
        }
 
-       strlcat(buf, "]", sizeof buf);
+       (void)strlcat(buf, "]", sizeof buf);
 
        return (buf);
 }
@@ -1818,12 +1820,12 @@ mta_relay_show(struct mta_relay *r, struct mproc *p, uint32_t id, time_t t)
 
        flags[0] = '\0';
 
-#define SHOWSTATUS(f, n) do {                                          \
-               if (r->status & (f)) {                                  \
-                       if (flags[0])                                   \
-                               strlcat(flags, ",", sizeof(flags));     \
-                       strlcat(flags, (n), sizeof(flags));             \
-               }                                                       \
+#define SHOWSTATUS(f, n) do {                                                  \
+               if (r->status & (f)) {                                          \
+                       if (flags[0])                                           \
+                               (void)strlcat(flags, ",", sizeof(flags));       \
+                       (void)strlcat(flags, (n), sizeof(flags));               \
+               }                                                               \
        } while(0)
 
        SHOWSTATUS(RELAY_WAIT_MX, "MX");
@@ -1835,11 +1837,11 @@ mta_relay_show(struct mta_relay *r, struct mproc *p, uint32_t id, time_t t)
 #undef SHOWSTATUS
 
        if (runq_pending(runq_relay, NULL, r, &to))
-               snprintf(dur, sizeof(dur), "%s", duration_to_text(to - t));
+               (void)snprintf(dur, sizeof(dur), "%s", duration_to_text(to - t));
        else
-               strlcpy(dur, "-", sizeof(dur));
+               (void)strlcpy(dur, "-", sizeof(dur));
 
-       snprintf(buf, sizeof(buf), "%s refcount=%d ntask=%zu nconn=%zu lastconn=%s timeout=%s wait=%s%s",
+       (void)snprintf(buf, sizeof(buf), "%s refcount=%d ntask=%zu nconn=%zu lastconn=%s timeout=%s wait=%s%s",
            mta_relay_to_text(r),
            r->refcount,
            r->ntask,
@@ -1854,18 +1856,18 @@ mta_relay_show(struct mta_relay *r, struct mproc *p, uint32_t id, time_t t)
        while (tree_iter(&r->connectors, &iter, NULL, (void **)&c)) {
 
                if (runq_pending(runq_connector, NULL, c, &to))
-                       snprintf(dur, sizeof(dur), "%s", duration_to_text(to - t));
+                       (void)snprintf(dur, sizeof(dur), "%s", duration_to_text(to - t));
                else
-                       strlcpy(dur, "-", sizeof(dur));
+                       (void)strlcpy(dur, "-", sizeof(dur));
 
                flags[0] = '\0';
 
-#define SHOWFLAG(f, n) do {                                            \
-               if (c->flags & (f)) {                                   \
-                       if (flags[0])                                   \
-                               strlcat(flags, ",", sizeof(flags));     \
-                       strlcat(flags, (n), sizeof(flags));             \
-               }                                                       \
+#define SHOWFLAG(f, n) do {                                                    \
+               if (c->flags & (f)) {                                           \
+                       if (flags[0])                                           \
+                               (void)strlcat(flags, ",", sizeof(flags));       \
+                       (void)strlcat(flags, (n), sizeof(flags));               \
+               }                                                               \
        } while(0)
 
                SHOWFLAG(CONNECTOR_NEW,         "NEW");
@@ -1886,7 +1888,7 @@ mta_relay_show(struct mta_relay *r, struct mproc *p, uint32_t id, time_t t)
                SHOWFLAG(CONNECTOR_LIMIT_DOMAIN,        "LIMIT_DOMAIN");
 #undef SHOWFLAG
 
-               snprintf(buf, sizeof(buf),
+               (void)snprintf(buf, sizeof(buf),
                    "  connector %s refcount=%d nconn=%zu lastconn=%s timeout=%s flags=%s",
                    mta_source_to_text(c->source),
                    c->refcount,
@@ -2009,10 +2011,10 @@ mta_host_to_text(struct mta_host *h)
        static char buf[1024];
 
        if (h->ptrname)
-               snprintf(buf, sizeof buf, "%s (%s)",
+               (void)snprintf(buf, sizeof buf, "%s (%s)",
                    sa_to_text(h->sa), h->ptrname);
        else
-               snprintf(buf, sizeof buf, "%s", sa_to_text(h->sa));
+               (void)snprintf(buf, sizeof buf, "%s", sa_to_text(h->sa));
 
        return (buf);
 }
@@ -2141,7 +2143,7 @@ mta_source_to_text(struct mta_source *s)
 
        if (s->sa == NULL)
                return "[]";
-       snprintf(buf, sizeof buf, "%s", sa_to_text(s->sa));
+       (void)snprintf(buf, sizeof buf, "%s", sa_to_text(s->sa));
        return (buf);
 }
 
@@ -2203,7 +2205,7 @@ mta_connector_to_text(struct mta_connector *c)
 {
        static char buf[1024];
 
-       snprintf(buf, sizeof buf, "[connector:%s->%s,0x%x]",
+       (void)snprintf(buf, sizeof buf, "[connector:%s->%s,0x%x]",
            mta_source_to_text(c->source),
            mta_relay_to_text(c->relay),
            c->flags);
@@ -2310,7 +2312,7 @@ mta_route_to_text(struct mta_route *r)
 {
        static char     buf[1024];
 
-       snprintf(buf, sizeof buf, "%s <-> %s",
+       (void)snprintf(buf, sizeof buf, "%s <-> %s",
            mta_source_to_text(r->src),
            mta_host_to_text(r->dst));
 
@@ -2428,8 +2430,8 @@ mta_hoststat_update(const char *host, const char *error)
                tree_init(&hs->deferred);
                runq_schedule(runq_hoststat, tm+HOSTSTAT_EXPIRE_DELAY, NULL, hs);
        }
-       strlcpy(hs->name, buf, sizeof hs->name);
-       strlcpy(hs->error, error, sizeof hs->error);
+       (void)strlcpy(hs->name, buf, sizeof hs->name);
+       (void)strlcpy(hs->error, error, sizeof hs->error);
        hs->tm = time(NULL);
        dict_set(&hoststat, buf, hs);